Ascites (GI) Flashcards
Define ascites.
A pathological collection of fluid in the peritoneal cavity in the abdomen
What is the most common cause of ascites?
Cirrhosis - approximately 75% of cases
What quantitative measure can indicate the cause of ascites and how can we calculate this?
Serum ascites albumin gradient OR serum to ascitic fluid albumin gradient (SAAG)
[Serum albumin] - [Ascites albumin]
How can SAAG be classified in ascites?
- SAAG>11g/L: transudative ascitic fluid (low-protein, hypoalbuminaemia) = peritoneal cause
- SAAG<11g/L: exudative ascitic fluid (high-protein) = portal hypertension
What are some causes of transudative ascites (SAAG>11g/L)? (6)
- portal hypertension - abnormally high pressure within hepatic portal vein
- cirrhosis
- congestive HF
- alcohol-related liver disease (ALD)
- liver failure
- Budd-Chiari syndrome (hepatic vein thrombosis)
What signs are seen in portal hypertension (cause of transudative ascites)? (3)
- caput medusae
- splenomegaly
- ascites
How do we treat oesophageal varices if present in ascites/portal hypertension?
- terlipressin + IV Abx
- possibly TIPS (transjugular intrahepatic portosystemic shunt)
- to stop endoscopic bleeding - variceal band ligation (but not if uncontrolled haemorrhage, must use sengstaken-blakemore tube)
- prophylaxis: beta blockers
What are the causes of exudative ascites (SAAG<11g/L)? (4)
- hypoalbuminaemia (nephrotic syndrome, severe malnutrition e.g. Kwashikor)
- intra-abdominal malignancy with peritoneal spread
- infections e.g. TB
- pancreatitis
What are the clinical features of ascites? (5)
- abdominal distension
- early satiety
- weight gain
- dyspnoea
- hepatic encephalopathy - change in handwriting, altered sleep pattern, confusion–>coma
What would you see on examination in ascites? (3 + 3)
- distended abdomen
- shifting dullness (change from dull to resonant when patient changes from supine to lateral decubitus position)
- signs of underlying disease:
- chronic liver disease/cirrhosis - jaundice, spider naevi, palmar erythema, muscle wasting, leukonychia, hepatomegaly/splenomegaly
- heart failure - elevated JVP
- upper abdominal malignancy - Virchow’s node and weight loss
What are some risk factors for ascites? (3)
- potential precipitating factors e.g. dehydration/AKI, hypokalaemia, GI bleed, sepsis
- cirrhosis risk factors e.g. hepatitis
- Fx - haemochromatosis
What is the first-line investigation for new-onset ascites?
Abdominal ultrasound
What investigations are done for ascites? (4)
- abdominal US
- ascitic fluid analysis (underlying cause)
- diagnostic paracentesis (rule out spontaneous bacterial peritonitis which shows polymorphonuclear leukocyte count >250/mm2)
- haematocrit (rule out haematoperitoneum)
What are some common vs uncommon differential diagnoses for ascites?
- common: hepatitis C, ALD, congestive HF, nephrotic syndrome, pancreatitis
- uncommon: hepatitis B, primary biliary cholangitis, autoimmune hepatitis, haemochromatosis, Wilson’s disease, constrictive pericarditis, Budd-Chiari syndrome, chronic renal failure, protein-losing enteropathy
Describe the general management plan for ascites. (5)
- diuretics: spironolactone (aldosterone antagonist) +/- furosemide
- reduce dietary sodium
- therapeutic paracentesis (drainage in tense ascites) - give IV albumin when large volume paracentesis
- fluid restriction in hyponatraemia <125
- monitor weight daily
